Hufflepuff for sure, Eilonwy is very fair and patient, much más so than Taran most of the time (like with Gurgi), basically good-natured until someone is unnecessarily rude to her and takes her for granted and she has to put them in her place. (This does happen to Puffs ALLLL the time- they're usually quite humble and don't ask for trophies, so we sometimes get our help overlooked and stepped on.) She opens up to others emotionally with ease and doesn't really care about glory and fame like Taran.